1988 GMC C1500 Hesitation from a stop

Hello, First things first my 1988 GMC Sierra 5.7L with 150,000 milles was running rough at idle but only after warm-up, and after driving SES would pop-up with a Code 32 present. So I replaced the EGR Valve after vaccum testing it, and it wasnt holding vaccum: easy fix. Only now shortly after starting, and driving down the street when I come to a complete stop, and proceed to depress the gas pedal the truck begins to hesitate or sometimes stalls completely! After replacing the egr solenoid, o2 sensor, TPS, distributor cap, rotor, spark plugs, and fuel filter I am at my wits end since I have no other error codes to work with. Thank you for your patience!